Top 7 Interview Questions On Microservices Architecture

Microservices Architecture has gained significant traction in the realm of software development, offering a modular and scalable approach to building applications. As organizations embrace this architectural style, it becomes crucial for interviewers to assess candidates’ understanding and expertise in Microservices. In this blog, we’ll delve into the top interview questions related to Microservices Architecture, providing insightful answers to guide both interviewers and candidates.

Who can expect this question?

These questions are tailored for individuals aspiring for roles related to software development, system architecture, and DevOps. Professionals aiming for positions such as Software Engineer, System Architect, DevOps Engineer, or anyone involved in designing and maintaining distributed systems will find these questions pertinent.

Q1: What is Microservices Architecture?

Answer: Microservices architecture is a method for developing applications as a group of independent services connected using synchronous or asynchronous events to achieve a common goal. Some characteristics of microservices architecture are

Each service can be independently deployed, updated, and tested.
Each service can be independently scaled to meet the customer demand.
These Services can be developed using different languages and tools and deployed independently
Micros Services Communicate with each other via API calls or Queuingin services.

Q2: How do Microservices communicate with each other?

Answer : There are several ways through which Microservices can communicate with each other.

Rest API : This is most commonly used for Communication. This is Lightweight and Secure way of Communication
Message Passing: Managed Message Queuing Services like SQS or RabitMq is also used for Communication.
Streaming or Event-Driven Service: Database triggers or Streaming Services can also be used for Communication.

Q3: What are the advantages of Microservices over Monolithic Architecture?

Answer: Imagine building a massive castle – that’s Monolithic architecture. Now, think about Lego pieces – that’s Microservices. Here’s why Microservices are the cool kids on the block:

Freedom to Evolve: In the Monolithic, changing one thing means messing with the whole castle. Microservices? You tweak one piece without worrying about the entire structure crashing down. It’s like upgrading your knight’s armor without redoing the whole kingdom.
Scaling Simplified: In Monolithic land, when the kingdom gets crowded, you have to expand the entire castle. Microservices let you build more towers or add more soldiers where needed. It’s like adding rooms when your castle becomes the go-to spot.
Language Flexibility: Monolithic says, “Stick to my language!” Microservices are cool; they’re multilingual. Each piece can speak its language. It’s like having knights, wizards, and archers in the same castle, each talking their lingo.
Communication on Point: Monolithic relies on one central command. Microservices? They’re like a team that communicates efficiently, passing messages smoothly. It’s as if every Lego piece knows when to connect with the others.

Q4: What is Service Discovery?

Answer: Service Discovery in Microservices is like having a city planner for a dynamic urban landscape. In this context, Microservices act as skyscrapers, each providing a specific function. The Service Discovery mechanism functions as a real-time map, keeping track of the services’ locations and statuses.

In practical terms, when a Microservice emerges or relocates, it registers itself with the Service Discovery system. This registration includes essential information such as its network location and availability. Conversely, when a service needs to communicate with another, it consults the Service Discovery system to dynamically locate the required service.

This orchestrated process ensures seamless and efficient communication among Microservices, allowing the system to adapt to changes without requiring explicit configuration. Service Discovery is the silent orchestrator, ensuring the Microservices metropolis remains well-connected and agile.

Q5: How do Microservices ensure data consistency in a distributed system?

Answer : Microservices achieve data consistency through a few key techniques:

Eventual Consistency: Instead of insisting on instant agreement, Microservices are cool with the idea that it might take a bit for everyone to be on the same page. It’s like the musicians finishing their notes in their own time but making sure the final melody is perfect.
Saga Pattern: Think of this as a musical storyline. Each service is responsible for its own part of the plot. If something goes off-key, there’s a plan (a saga) to fix it, ensuring the overall narrative (data consistency) is maintained.
Distributed Transactions: Microservices handle transactions like a synchronized dance. Even if each dancer (service) has its own moves, they follow a choreography that ensures the performance (data consistency) is flawless.
Compensating Actions: If something goes out of tune, Microservices have a backup plan – compensating actions. It’s like a musician correcting a wrong note swiftly to keep the melody intact.

Let’s take a scenario of Online Purchase Transaction

Order Service: When a customer places an order, the Order Service is responsible for recording the order details.
Payment Service: Upon receiving the “OrderPlaced” event, the Payment Service is triggered to process the payment. It publishes an “OrderPlaced” event indicating a successful order placement.It debits the customer’s account and publishes a “PaymentProcessed” event.

Now, let’s consider the strategies for ensuring data consistency:

Eventual Consistency:
- The “OrderPlaced” event is immediately broadcasted, even before the payment is processed.
- It’s okay if the payment processing takes a bit of time. Eventually, the system ensures that the order and payment data align.
Saga Pattern:
- Imagine the Payment Service encounters an issue processing the payment after the “OrderPlaced” event.
- The system initiates a saga to either complete the payment or roll back the order placement, ensuring a consistent state.
Distributed Transactions:
- Both the Order and Payment services participate in a distributed transaction.
- If any step fails (e.g., payment processing), the entire transaction is rolled back, maintaining a consistent state across services.
Compensating Actions:
- If the Payment Service faces an issue after processing the payment, it triggers a compensating action, such as refunding the payment, to rectify any inconsistencies.

In this example, the orchestration of events and transactions between the Order and Payment services showcases how Microservices employ different strategies to ensure data consistency in a distributed system, creating a seamless and reliable online purchase experience for customers.

Q6 : What are the different types of triggers used to communicate with Microservices?

HTTP/REST API Calls: Direct and synchronous communication through well-defined HTTP endpoints.
Messaging Queues: Asynchronous communication using message queues, decoupling services in time.
Event-driven Architecture: Services communicate through events, allowing for loosely coupled and scalable interactions.
Webhooks: Real-time notifications through HTTP requests, often used in event-driven scenarios.
API Gateways: Centralized entry point managing requests, handling load balancing, and simplifying communication for Microservice

Q7: What are the challenges associated with Microservices deployment and orchestration?

Here are some common challenges associated with Microservices deployment and orchestration:

Service Discovery and Registration: Microservices need to discover each other dynamically in a changing environment. Maintaining an up-to-date service registry and handling service registration and deregistration can be challenging.

Versioning and Compatibility: Managing multiple versions of Microservices and ensuring backward and forward compatibility during updates can be complex. Compatibility issues may arise, impacting the overall system.

Configuration Management: Coordinating configurations across numerous Microservices can be daunting. Ensuring that each service has the correct configuration settings for its environment adds a layer of complexity.

Monitoring and Logging: With the distributed nature of Microservices, monitoring, and logging become crucial. Aggregating and correlating logs, as well as monitoring the performance and health of each service, pose challenges.

Dependency Management: Microservices often have dependencies on external services, libraries, or databases. Managing these dependencies and handling potential failures or changes in these external components requires careful consideration.

Data Consistency: Ensuring data consistency across Microservices can be challenging in a distributed system. Implementing strategies like eventual consistency or distributed transactions is necessary but adds complexity.

Security Concerns: Microservices need robust security mechanisms. Managing authentication, authorization, and securing communication between services requires careful planning and implementation.

Scalability and Load Balancing: Scaling individual Microservices to handle varying workloads and orchestrating load balancing across services can be challenging. Ensuring optimal resource utilization while accommodating changes in demand is a balancing act.

Deployment Automation: Implementing automated deployment pipelines for Microservices is essential. However, creating and maintaining effective deployment automation, including testing and rollback strategies, can be complex.